The present invention relates to a semiconductor device, a data processing system, and a semiconductor device control method which are used, for example, to store compressed data in an external memory.
Recently, semiconductor devices are widely used which perform various arithmetic processing including image processing. When, in such semiconductor devices, data such as image data is written to a memory or is read from a memory, data is encoded, decoded, compressed, and expanded conforming to a predetermined standard. Concerning reading of compressed data, the techniques disclosed in Japanese Unexamined Patent Application Publication Nos. Hei 10 (1998)-27127 and 2006-099774 are known.
In the technique disclosed in Japanese Unexamined Patent Application Publication No. Hei 10 (1998)-27127, when compressed data is stored in a memory, memory address information indicating where the compressed data is stored is stored in the memory via a bus as auxiliary information for use in reading the compressed data. The address information is used when the compressed data is to be read from the memory.
In the technique disclosed in Japanese Unexamined Patent Application Publication No. 2006-099774, when compressed data is stored in a memory, data size information about the compressed data is stored as auxiliary information in a direct memory access controller (DMAC) via a bus. The data size information is used when the compressed data is to be read from the memory.